require 'optparse'

module VagrantPlugins
  module RemoveOldVersions
    class Command < Vagrant.plugin("2", :command)
      def self.synopsis
        "remove all but the latest installed boxes"
      end

      def execute
        options = {}
        options[:force] = false
        options[:dry_run] = false

        opts = OptionParser.new do |o|
          o.banner = "Usage: vagrant remove-old-versions [options]"
          o.separator ""
          o.separator "Options:"
          o.separator ""

          o.on("-p PROVIDER", "--provider PROVIDER", String, "The specific provider type for the boxes to destroy.") do |p|
            options[:provider] = p
          end

          o.on("-n", "--dry-run", "Only print the boxes that would be removed.") do |f|
            options[:dry_run] = f
          end

          o.on("--name NAME", String, "The specific box name to destroy.") do |name|
            options[:name] = name
          end

          o.on("-f", "--force", "Destroy without confirmation even when box is in use.") do |f|
            options[:force] = f
          end
        end

        # Parse the options
        argv = parse_options(opts)
        return if !argv

        boxes = @env.boxes.all.sort
        if boxes.empty?
          return @env.ui.warn(I18n.t("vagrant.commands.box.no_installed_boxes"), prefix: false)
        end

        delete_oldest_boxes(boxes, options[:provider], options[:force], options[:name], options[:dry_run])

        # Success, exit status 0
        0
      end

      private

      def delete_oldest_boxes(boxes, only_provider, skip_confirm, only_name, dry_run)
        # Find the longest box name
        longest_box = boxes.max_by { |x| x[0].length }
        longest_box_length = longest_box[0].length

        # Hash map to keep track of newest versions
        newest_boxes = Hash.new

        # First find the newest version for every installed box
        boxes.each do |name, version, provider|
          next if only_provider and only_provider != provider.to_s
          next if only_name and only_name != name

          # Nested to make sure it works for boxes with different providers
          if newest_boxes.has_key?(name)
            if newest_boxes[name].has_key?(provider)
              saved = Gem::Version.new(newest_boxes[name][provider])
              current = Gem::Version.new(version)
              if current > saved
                newest_boxes[name][provider] = version
              end
            else
              newest_boxes[name][provider] = version
            end
          else
            newest_boxes[name] = Hash.new
            newest_boxes[name][provider] = version
          end
        end

        @env.ui.info("The following boxes will be kept...");
        newest_boxes.each do |name, providers|
          providers.each do |provider, version|
            @env.ui.info("#{name.ljust(longest_box_length)} (#{provider}, #{version})")

            @env.ui.machine("box-name", name)
            @env.ui.machine("box-provider", provider)
            @env.ui.machine("box-version", version)
          end
        end

        @env.ui.info("", prefix: false)
        @env.ui.info("Checking for older boxes...");

        # Track if we removed anything so the user can be informed
        removed_any_box = false
        boxes.each do |name, version, provider|
          next if !newest_boxes.has_key?(name) or !newest_boxes[name].has_key?(provider)

          current = Gem::Version.new(version)
          saved = Gem::Version.new(newest_boxes[name][provider])
          if current < saved
            removed_any_box = true

            # Use the remove box action
            if dry_run
              @env.ui.info("would remove #{name} #{provider} #{version}")
            else
              @env.action_runner.run(Vagrant::Action.action_box_remove, {
                  box_name: name,
                  box_provider: provider,
                  box_version: version,
                  force_confirm_box_remove: skip_confirm,
                  box_remove_all_versions: false,
              })
            end
          end
        end

        if !removed_any_box
          @env.ui.info("No old versions of boxes to remove...");
        end
      end
    end
  end
end
